The subject matter described herein relates generally to rotary machines and more particularly, to a sealing assembly and methods of assembling a rotary machine.
At least some known turbomachines such as, for example, gas turbine engines include a combustor, a compressor coupled downstream from the combustor, a turbine, and a rotor assembly rotatably coupled between the compressor and the turbine. Some known rotor assemblies include a rotor shaft, at least one rotor disk coupled to the rotor shaft, and a plurality of circumferentially-spaced turbine buckets that extend outwardly from each rotor disk. Each turbine bucket includes an airfoil that extends radially outward from a platform towards a turbine casing.
During operation of at least some known turbines, the compressor compresses air that is subsequently mixed with fuel prior to being channeled to the combustor. The mixture is then ignited to generate hot combustion gases that are channeled to the turbine. The rotating turbine blades or buckets channel high-temperature fluids, such as combustion gases, through the turbine. The turbine extracts energy from the combustion gases for powering the compressor, as well as producing useful work to power a load, such as an electrical generator, or to propel an aircraft in flight.
At least some known turbine engines include a sealing assembly that includes a plurality of stator labyrinth teeth that extend outwardly from a turbine casing towards each turbine bucket to reduce air leakage/air flow between the airfoil and the turbine casing. At least a portion of combustion gases channeled through the turbine are undesirably channeled between a tip end of the turbine bucket and the turbine casing as tip clearance losses. Over time, the labyrinth teeth may begin to oxidize and/or wear as the combustion gases contact the labyrinth teeth, which may increase tip clearance losses and/or reduce an operating efficiency of the turbine.